1. Field of the Invention
The present invention relates to a head-mounted display apparatus.
2. Description of Related Art
Heretofore, there is a head-mounted display apparatus as a display apparatus arranged to be mountable on a part of the body, such as the head, of a user and to display an image supplied from outside in such a way as to be observable by the user with the display apparatus in a state of being mounted on the head of the user.
Such a head-mounted display apparatus will be described with reference to FIG. 1. FIG. 1 is a block diagram showing the arrangement of the conventional head-mounted display apparatus.
The head-mounted display apparatus is provided, as shown in FIG. 1, with an O/E detecting circuit 132 for inputting a video signal (NTSC signal) supplied from outside, for example, a TV tuner or a video reproducing apparatus. The O/E detecting circuit 132 is a circuit provided for detecting whether the inputted video signal is a video signal for the left eye (left-eye video signal) or a video signal for the right eye (right-eye video signal). A detection signal indicative of a result of the detection by the O/E detecting circuit 132 is inputted to a control means 130. Further, the video signal inputted to the O/E detecting circuit 132 is supplied to a decoder processing part 102.
The decoder processing part 102 converts the inputted video signal into R, G and B signals, and the R, G and B signals are inputted to a display driver 103. The display driver 103 supplies the inputted R, G and B signals to a left-eye display system 104 or a right-eye display system 118 on the basis of a control signal from the control means 130. Here, the control means 130 discriminates whether the inputted video signal is the left-eye video signal or the right-eye video signal, on the basis of the detection signal from the O/E detecting circuit 132, and, when the inputted video signal is the left-eye video signal, outputs a control signal for instructing the display driver 103 to supply the R, G and B signals to the left-eye display system 104, and, when the inputted video signal is the right-eye video signal, outputs a control signal for instructing the display driver 103 to supply the R, G and B signals to the right-eye display system 118.
The left-eye display system 104 has a liquid crystal display element 113 for receiving the R, G and B signals from the display driver 103 and displaying a video image represented by the R, G and B signals. The liquid crystal display element 113 is illuminated from the back side thereof by a back light 107, which is driven by a driver 105. A video image displayed on the liquid crystal display element 113 is enlarged by an optical element 115 and is then led to the left eye 125 of the user. More specifically, in the optical element 115, light having passed through the liquid crystal display element 113 from the back light 107 enters an entrance surface 109. The entering light is made incident on a reflecting surface 111 at an angle more than a critical angle to be totally reflected at the reflecting surface 111. Then, the light is made incident on a half-mirror 117 to be reflected toward the reflecting surface 111. The light reflected from the half-mirror 117 enters the reflecting surface 111 at an angle less than the critical angle and, then, exits toward the left eye 125 of the user. On the left eye 125, the light from the optical element 115 is focused to form an image.
The right-eye display system 118 has, similarly to the left-eye display system 104, a liquid crystal display element 123, an optical element 128, a back light 121 and a driver 119, and is arranged to enlarge, by the optical element 128, a video image displayed on the liquid crystal display element 123 and, then, lead the video image to the right eye (not shown) of the user.
To the blocks including the display driving circuit 103 and the drivers 105 and 119, the respective applicable driving voltages are supplied from a power supply circuit 101. The power supply circuit 101 receives electric power from an external power supply 101a through a power supply switch 101b and forms the driving voltages to be supplied to the respective blocks.
In the above-mentioned head-mounted display apparatus, it is necessary to correctly mount the apparatus on the head of the user in such a way as to cause right and left video images to naturally merge with each other. For that purpose, the head-mounted display apparatus has such an arrangement that mounting-state confirming figures are supplied to the respective display systems for the right eye and the left eye from an external apparatus so as to enable the user to confirm the mounting state of the head-mounted display apparatus by observing the mounting-state confirming figures displayed on the respective display systems.
However, in the above-mentioned conventional head-mounted display apparatus, since, in the event of confirming the mounting state thereof, the mounting-state confirming figures are displayed simultaneously on the right-eye and left-eye display systems, the user is required to observe the respective figures simultaneously with both the right and left eyes. Therefore, it is very difficult for the user to confirm whether each of the displayed figures for the right and left eyes is clearly seen. As a result, it is impossible to know whether the mounting state of the head-mounted display apparatus is appropriate or not.
It is an object of the invention to provide a head-mounted display apparatus capable of enabling the user to correctly know the mounting state of the head-mounted display apparatus, and a mounting-state conforming method for use in the head-mounted display apparatus.
To attain the above object, in accordance with an aspect of the invention, there is provided a head-mounted display apparatus which comprises left-eye image display means, right-eye image display means, a mounting unit arranged to support the left-eye image display means and the right-eye image display means and to be mountable on a part of the body of a user, figure generating means for generating a mounting-state confirming figure for confirming a mounting state of the mounting unit when the mounting unit has been mounted on the part of the body of the user, operation inputting means for inputting a confirmation operation when the user has confirmed the mounting state of the mounting unit, control means for selecting, in accordance with the inputting of the confirmation operation, one of a state of displaying the mounting-state confirming figure both on the left-eye image display means and the right-eye image display means, a state of displaying the mounting-state confirming figure on one of the left-eye image display means and the right-eye image display means, and a state of displaying the mounting-state confirming figure on another of the left-eye image display means and the right-eye image display means.
It is another object of the invention to provide a head-mounted display apparatus arranged to, surely and at good timing, give warning of long-time usage to a user and having an improved operability.
It is a further object of the invention to provide a head-mounted display apparatus arranged to, timely and surely, give warning of long-time usage, etc., to a user in accordance with the mounting state of the head-mounted display apparatus or the inputting state of a video signal.
It is a still further object of the invention to provide a head-mounted display apparatus capable of enabling a user to surely recognize the mounting state of the head-mounted display apparatus.
These and further objects and features of the invention will become apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawings.